1.3 Acoustical Testing 31 2. Using the sound level meter, take a reading near the loudspeaker (at about 1 m) and on-axis. At this distance, the direct sound field will dominate the measurement. 3. Move away from the loudspeaker while observing the sound level meter. The sound level will fall off as you move farther away. If you are in a room with a reverberant sound field, at some distance the meter reading will quit dropping. You have now moved beyond critical distance. Measurements of the direct field beyond this point will be a challenge for some types of analysis. Move back toward the loudspeaker until the meter begins to rise again. You are now entering a good region to per- form acoustic measurements on loudspeakers in this environ- ment. The above process provides an estimate that is adequate for positioning a measurement microphone for loudspeaker testing. With a mic placement inside of critical distance, the direct field is a more dominant feature on the impulse response